fusion ignited

Fusion ignition occurs when the fusion reaction in a plasma produces enough energy to sustain itself without external input. In stellar terms, it's like the sun burning steadily because its core's nuclear reactions generate enough heat and pressure to keep going. For fusion on Earth, this means the energy released from fusing isotopes like hydrogen exceeds the energy needed to initiate and maintain those reactions. Achieving ignition is a key goal for fusion energy because it signifies a self-sustaining and efficient process, potentially providing a virtually unlimited, clean energy source.